UPDATE AS OF DECEMBER 15, 2022: The Lucy team updated the spacecraft’s attitude controller on Dec. 6, resolving the previously observed vibration interaction between the controller and the solar array structural modes. As previously reported, the vibration was too small to pose a risk and the spacecraft continues to operate safely.
The team resumed solar array deployment activities, with an attempt on Dec. 13 that did not result in a latch. Since the estimated progress in deployment has decreased to minimal levels, the likelihood of a latch in the current thermal environment is very low. The team has therefore made the decision to suspend additional re-deployment activities through 2022. Future opportunities may be considered after careful analysis of the data and as the thermal environment changes.
Now that NASA’s Lucy spacecraft has successfully carried out its first Earth gravity assist, it has resumed high-data-rate communication with Earth. The Lucy spacecraft continues to operate safely and progress toward its mission goals.
Earlier this year, the team executed a series of commands to further deploy the spacecraft’s unlatched solar array. While deployment attempts were paused during a period of low-data-rate communications, the team continued to analyze the spacecraft’s telemetry and carry out ground-based tests. Based on these analyses, the team decided to continue attempts to further deploy the solar array. The likelihood of mission success in the current unlatched state is high, however the team expects that additional deployment—or potential latch—only improves confidence in performance without jeopardizing the spacecraft’s safety.
On Monday, Nov. 7, the spacecraft was instructed to point toward the Sun and operate the array deployment motors for a short period of time. As expected, the latest attempt deployed the wing incrementally forward, but it did not latch. The operation did succeed in providing the team with data to evaluate the array’s status and ascertain any changes since the last deployment attempt on June 16. During this analysis, the team identified that a small vibration occurred as the unlatched array interacted with the spacecraft’s attitude controller while the array was pointed toward Earth and at a cold temperature. The vibration did not occur as a result of the deployment activity itself. While this vibration is too small to pose a risk to the spacecraft in its current state, further array deployment attempts have been paused while the attitude controller is updated to resolve this issue. In the meantime, the spacecraft was reoriented so that the array is warmer, and the team found that the vibration is not present. The team will re-evaluate further redeployment activities once the updates to the controller are checked out on the spacecraft.
All of Lucy’s instruments functioned as expected during the gravity assist and provided an excellent test of the spacecraft’s systems and mission procedures. The team is continuing to analyze the images of the Earth and Moon collected during the flyby.